Nonaka Koji, Une S, Tatsuta N, Ito K, Akiyama J
Osaka Prefecture University Department of Physical Therapy 6-7-30 Habikino, Habikino Osaka 583-8555 Japan.
Shujitsu Junior College Department of Living Science Okayama Japan.
Acta Physiol Hung. 2014 Dec;101(4):421-8. doi: 10.1556/APhysiol.101.2014.007.
We investigated muscle atrophy, major antioxidant enzymes and lipid peroxidation in the extensor digitorum longus (EDL, predominantly fast fibers) and soleus (predominantly slow fibers) muscle of streptozotocin-diabetic rats. Female Wistar rats were divided into a control (n = 5) and streptozotocin-induced diabetic group (n = 5). Eight weeks after diabetes induction the EDL and soleus muscles were removed and catalase (CAT), glutathione peroxidase (GPX) and superoxide dismutase activity (SOD), and thiobarbituric acid reactive substances (TBARS) levels measured. The CAT activity increased in both the EDL and soleus muscles of the diabetic rats (p < 0.01), whereas the GPX and SOD activities were increased only in the EDL muscle (p < 0.01 and p < 0.05). The TBARS levels were only increased in the EDL muscle of the diabetic rats (p < 0.01). Both muscles showed significant atrophy but the EDL muscle elicited the greatest atrophy. In conclusion, it appears that adaptive responses to oxidative stress were adequate in the soleus muscle, but not in the EDL muscle, of diabetic rats. Thus fast twitch muscle fibers may be more susceptible to oxidative stress than slow twitch muscle fibers and this may contribute to muscle atrophy under diabetic conditions.
我们研究了链脲佐菌素诱导的糖尿病大鼠的趾长伸肌（EDL，主要为快肌纤维）和比目鱼肌（主要为慢肌纤维）中的肌肉萎缩、主要抗氧化酶和脂质过氧化情况。将雌性Wistar大鼠分为对照组（n = 5）和链脲佐菌素诱导的糖尿病组（n = 5）。糖尿病诱导8周后，取出EDL和比目鱼肌，测量过氧化氢酶（CAT）、谷胱甘肽过氧化物酶（GPX）和超氧化物歧化酶活性（SOD）以及硫代巴比妥酸反应性物质（TBARS）水平。糖尿病大鼠的EDL和比目鱼肌中CAT活性均增加（p < 0.01），而GPX和SOD活性仅在EDL肌肉中增加（p < 0.01和p < 0.05）。TBARS水平仅在糖尿病大鼠的EDL肌肉中升高（p < 0.01）。两块肌肉均出现明显萎缩，但EDL肌肉萎缩最为明显。总之，糖尿病大鼠比目鱼肌对氧化应激的适应性反应似乎足够，但EDL肌肉则不然。因此，快肌纤维可能比慢肌纤维更容易受到氧化应激的影响，这可能导致糖尿病条件下的肌肉萎缩。
